The invention concerns in particular the case of containers consisting of a bottle for liquid, able to contain at least around ten litres of liquid, in particular water, typically bottles for water of three, four or five gallons, which are used in an inverted position in dispensing fountains. The neck of these bottles is closed by a cap generally referred to as “snapped on”, that is to say a cap the tubular skirt of which is able to be clipped internally or, more generally, wedged coaxially around the neck, unlike screwed caps for example. The majority of bottles of this type can be reused many times, having their cap removed and then cleaned before each filling.
In order to remove the cap easily vis-à-vis the neck, providing a weakened line on the skirt is known, which runs on at least a portion of the periphery of the skirt and along which a tear on the wall of the skirt propagates, initiated manually by the user. In the context of the bottles mentioned above, this weakened line generally includes a main part that is rectilinear and extends on the axial side, turned towards the free end of the skirt, internal reliefs on the skirt enabling it to be wedged on the neck in order to hold the cap around the neck: in this way, when this main part of the weakened line is broken, the whole part of the skirt situated between this main part of the weakened line and the free end of the skirt forms a strip that it is practical for the user to handle in order to pull, in the direction of the axis, on the remainder of the cap and thus forcibly release the latter vis-à-vis the neck. This being said, some users have a tendency to use the aforementioned strip to propagate the tearing of the skirt all around the neck, which they moreover mange to do easily, so that the lid of the cap and the skirt part remaining connected to this lid remain in place through the opening of the neck: the user must then grip this lid and/or this residual skirt part, in order to extract them from the neck. This handling in two stages is restrictive and sometimes proves to be difficult, or even almost impossible to perform with regard to the extraction of the remainder of the cap because of the strong interference between the neck and the internal reliefs on the skirt, necessarily present in the part of the skirt left in place after the aforementioned strip is pulled away.
These problems are partly dealt with by U.S. Pat. No. 7,581,653, on which is based the preamble of appended claim 1 and which proposes firstly to prevent the tearing of the skirt being propagated beyond what is necessary, by means of a stop for this tear, arranged projecting inside the skirt, in rectilinear extension of the main part of the weakened line, and, secondly, to extend the weakened line with a short segment that is parallel to the central axis of the skirt and is situated at the same axial level as the internal reliefs wedging the skirt around the neck.
This being so, the aim of the present invention is to improve existing caps by proposing arrangements that are both economical and further facilitate the release of the cap vis-à-vis the neck.